What you need to measure about Barack Obama, a likely potent adversary for the presidency, is that while he is a politically junior and consciously liberal-voting member of the U.S. Senate, he is actually a veteran Chicago politician with a fertile record of surprising associations in controversial events well apart from his work in legislatures.

Some few of these associations from his years in Chicago law work and urban development, and from his career in the Springfield, Illinois senate, speak to the quality of his judgment and to the strength of his character. Four associations in particular go the heart of the inquiry ahead in order to ask and answer the fundamental questions about who is Barack Obama.

The story focuses on four astute men who have little in common other than Mr. Obama: Messrs Rezko, Ayers, Khalidi and Auchi. Finding facts about Mr. Obama's exchanges with this quartet creates much of what can be called a political profile of candidate Obama.

Antoin "Tony" Rezko is the primary history to investigate for Mr. Obama's political profile. According to Mr. Obama, Mr. Rezko contacted the young law student when he was elected editor of the Harvard Law Review in 1990 and offered him employment in Chicago. Mr. Rezko, a Syrian-born U.S. citizen described by the Chicago press as a "fixer," is now in federal detention in Chicago and about to go on trial on March 3 for purloining up to $6 million from the people of Illinois with various kickback schemes while he was working for the present Democratic Governor, Rod Blagojevich. Mr. Rezko's involvement with the rapid rise of the political career of Mr. Obama long predates his work for the governor and remains largely unexamined. Mr. Obama joined a small Chicago law firm in 1993, Davis Miner Barnhill & Galland, that was then headed by Allison S. Davis, a politically connected man who would go on to become a partner with Mr. Rezko in real estate deals in Chicago and, much later, a large donor to the current mayor, Richard Daley, and to Governor Blagojevich and Senator Obama.

Through the connection of this law firm, Mr. Obama became a paid director of the progressive Woods Fund of Chicago, a sixty-seven-year-old philanthropy that later committed $1 million to a lucrative project developed by Mr. Davis in 2000 in partnership with Mr. Rezko. Meanwhile, Mr. Rezko advised and raised funds for Mr. Obama from his maiden entry into state politics in 1995-96, when he won a state senate seat from the 13th District, to his unsuccessful campaign for the U.S House of Representatives in 2000, to Mr. Obama's successful primary and general candidacy for the U.S. Senate in November 2004. Critically, Mr. Rezko became unusually entangled in the purchase of Mr. Obama's present home while Mr. Obama was a U.S. senator in June 2005.

Of his association with Mr. Rezko and the purchase of the Chicago home in the Hyde Park-Kenwood area, Senator Obama told George Stephanopoulos of ABC News "This Week" on January 27, 2008, "This is a story that has been out there for a year and has been thoroughly gnawed on by the press, both in Chicago and nationally. Tony Rezko was a friend of mine, a supporter, who I had known for 20 years. He was a contributor, not just to myself, but Democrats, as well as some Republicans throughout Illinois. Everybody perceived him as a businessman and a developer. He got into trouble that was completely unrelated to me, and nobody has suggested that I've been involved in any of those problems. I did make a mistake by purchasing a small strip of property from him, at a time where at that point he was under the cloud of a potential investigation. I've acknowledged that was a mistake. But again, nobody has suggested any wrongdoing, and I think at this point, it's important for people to recognize that I have actually provided all the information that's out there about it."

There is a deal to examine in this statement, offered coincidentally the day before Mr. Rezko's re-arrest and detention by order of U.S. District Judge Amy J. St. Eve, acting on a warrant by the U.S. Attorney for the Northern District of Illinois, Patrick Fitzgerald, that argued successfully that Mr. Rezko was a flight risk to Middle Eastern countries that do not have an extradition treaty with the United States.

One detail needing scrutiny for its possible inaccuracy is that the "mistake" that Mr. Obama made was not "purchasing a small strip of property from him." An established fact is that Mr. Obama did not purchase any property from Mr. Rezko. Mr. Obama bought a ten-foot-wide piece of a yard adjoining his home from Rita Rezko, Mr. Rezko's wife; and Mrs. Rezko purchased that corner lot of the original estate in part with the help of a $500,000 loan against unclear collateral from a local bank administered by another Rezko political associate in the governor's circle.

William Ayers is the second Chicago figure to consider in the political profile of Mr. Obama. William C. Ayers, known as Bill Ayers, is notorious as a terrorist bomber from the 1970s who, on September 11, 2001, in the New York Times was quoted as finding "a certain eloquence in bombs." Now, at 62, Mr. Ayers, a former aide to the current Mayor Richard M. Daley, is an established professor of education at the University of Illinois in Chicago. Importantly, Mr. Ayers and his wife, the equally notorious Weatherman terrorist Bernardine Dohrn, hosted a crucial meet-the-candidate event in their Hyde Park neighborhood home in 1995 when Mr. Obama, also a Hyde Park resident, was sounded out by vital citizens, among them the retiring state senator Alice Palmer for the 13th District.

In 1999, Mr. Ayers joined the Woods Fund of Chicago as a director and served alongside Mr. Obama for modest remuneration until Mr. Obama left the board on December 11, 2002; Mr. Ayers was for a time the chairman of the board. Also of note is the fact that Bernardine Dohrn works for Northwestern University Law School's Children and Family Justice Center, which received a grant from the Woods Fund in 2002.

Mr. Ayers, who has been described by one supporter as "friends" with Mr. Obama, openly speaks and writes of his role in the 1974 bombing of the U.S. Capitol Building where Mr. Obama now serves. Mr. Ayers is widely quoted from his reminiscence, which appeared in the New York Times on the infamous Tuesday, September 11, 2001: "I don't regret setting bombs. I feel we didn't do enough." When asked in that same interview if he would set more bombs today, his response was, "I don't want to discount the possibility."

Rashid Khalidi is the third Chicago citizen to consider in the political profile of candidate Obama. Now the voluble Edward Saïd Professor of Arab Studies and head of the Middle East Institute at Columbia University, Mr. Khalidi is said to have made Mr. Obama's acquaintance when they were colleagues at the University of Chicago, with Mr. Obama a lecturer at the law school and Mr. Khalidi a professor in Near Eastern Languages and Civilizations.

In Chicago in 1995, Mr. Khalidi and his wife Mona founded the Arab American Action Network (AAAN), a group associated with confrontational statements of support for Palestinians and antagonism toward Israel. In 2001 and again in 2002, the Woods Fund of Chicago, with directors Ayers and Obama, made grants of $40,000 and $35,000 to the AAAN. Importantly, the AAAN vice-president Ali Abunimah of Electronic Intifada has remembered Mr. Obama's speaking in 1999 against "Israeli occupation" at a charity event for a West Bank refugee camp; and Mr. Abunimah, an American citizen, Hyde Park resident and Princeton graduate, has also recalled Mr. and Mrs. Obama at a fundraiser held for the then-Congressional candidate Obama in 2000 at Rashid and Mona Khalidi's home, where Mr. Obama made convincing statements in support of the Palestinian cause.

There is also a report that Mr. Obama attended a farewell dinner for Professor Khalidi on the latter's appointment to Columbia University and move to New York, at which Mr.

Obama socialized with the Khalidis as well as with Edward Saïd, and at which Mr. Obama left a polite testimonial, as did Mayor Daley and Governor Blagojevich.

It is necessary to consider, in light of Mr. Obama's politically rich relationship with Mr. Khalidi and his colleagues, that Palestinian sources in Ramallah confirm, for Aaron

Klein of WorldNetDaily.com and my radio shows on WABC and KFI, that Rashid Khalidi was a paycheck-receiving PLO agent when it was formally named as a terrorist organization. In Beirut from 1976 to 1982, Mr. Khalidi headed the Palestinian press agency WAFA, for which his wife Mona Khalidi also worked. Mr. Khalidi also served Yasser Arafat's PLO at the Madrid conference in 1991. Mr. and Mrs. Khalidi have yet to comment on their reported political, financial and programmatic association with Mr. Obama in Chicago; as recently as last week neither of the Khalidis would speak on the telephone when asked about Mr. Obama, Mr. Rezko or Mr. Auchi.

The fourth name that contributes to the political profile of candidate Obama is Nadhmi Auchi of London, an Iraqi-born billionaire investor who founded his global enterprise General Mediterranean Holdings (GMH) in 1979 before he left Iraq.

Mr. Auchi apparently enters the political stage of Mr. Obama in 2003, when he was introduced to Mr. Rezko and became involved in developing a sixty-two-acre vacant lot along the Chicago River with his undercapitalized partner Mr. Rezko. Mr. Auchi is a prominent, mysterious figure, who was convicted in a French court in 2003 of political shenanigans in Iraqi oil contracts with regard French government officials and the oil giant TotalFinaElf. There are suspicions, never proven, of Mr. Auchi's commerce with Saddam Hussein, Muammar Qaddafi, and even the Byzantine and corrupt UN sanctions regime for Iraq called "Oil for Food."

In liberated Baghdad, Mr. Auchi is still regarded as a "Saddam guy" by Iraqi politicians. Nonetheless, Mr. Auchi has been linked with troubled communications systems contracts in Iraq; also, according to published Chicago Business reports, from 2004 to 2006 Mr. Auchi was linked with an aborted project by Mr. Rezko and another adventurous Chicago resident and former Illinois Institute of Technology classmate of Mr. Rezko's, Aihman Alsammarae, who in 2003 and 2004 was Iraq's Minister of Electricity, to build a power plant in Iraq. In April 2004, Mr. Auchi traveled to Illinois to meet with Mr. Rezko, Governor Blagojevich, State Senate President Emil Jones, Jr., and reportedly with then-State Senator Obama, who had just won the Democratic nomination for the U.S. Senate.

Prevented from returning to Chicago in November 2005 by the U.S. State Department, despite the written pleas of Mr. Rezko and others, Mr. Auchi has continued to make connections with Rezko affairs. The chief reason Mr. Rezko was rearrested on January 28, 2008, was because of allegedly hidden wire transfers in April and July 2007 of $3.7 million from Mr. Auchi's GMH via a Beirut bank to the accused and otherwise impoverished Mr. Rezko.

Considering the breadth and depth of the involvement of these four unusual men, Rezko, Ayers, Rashidi and Auchi, with the Chicago political journey and fortunes of Mr. Obama, it is reasonable to assume that more discovery will result in more anecdotes, comments, even electronic and paper records of the relationships. In April 2007, Mr. Obama, commenting about Mr. Rezko to the Chicago Sun-Times, anticipated many of the questions now being asked about his choice of political associations and his subsequent career decisions when he said, "One of the perils of public life is that you end up being responsible for, or you're being held responsible for, associations that you didn't necessarily know were a problem."

Finally, it is surprising to observe that the Democratic Party looks ready to nominate for the presidency a gifted Chicago politician, from the remnants of the old Richard Daley (father of the current mayor) machine, who asserts, against Mr. Obama's own established ideological and self-interested record, that he is "post-partisan."

There is a flickering presidential campaign analogy from the 1970s while you, Mr. McCain, were detained in Hanoi -- while Bill Ayers and Bernardine Dohrn were setting bombs, Mr. Rashidi was in the Mideast with the PLO, Mr. Auchi was in Baghdad with Saddam Hussein and Mr. Obama was eleven years old in Hawaii. In March and April 1972, Democratic primary voters elbowed aside Chicago Mayor Richard Daley's favorite, Ed Muskie of Maine, in order to nominate for the presidency the self-described "people's president," George McGovern of South Dakota. The Daley team telephoned Rowland Evans and Robert Novak to complain, "anybody but McGovern." The prescient quote from the Daley partisan: "I think the nomination of George McGovern would mean the end of the Democratic Party we have known."

Richard Nixon defeated George McGovern, forty-nine states to one. Will the four horsemen of Mr. Obama's November, Rezko, Ayers, Rashidi and Auchi, lead to a similar defeat for the spectacular candidacy of Barack Obama?

Mr. Batchelor is a veteran novelist, author of seven political romances and a short history of the Republican Party, and host of The John Batchelor Show, now on hiatus.